The Duke and Duchess of Cambridge swung into action today when they took part in an impromptu game of cricket.

William and Kate showed of their batting and bowling skills when they joined a group of youngsters and former sports stars promoting the 2015 Cricket World Cup in Christchurch, New Zealand.

But the Duchess was left a little shocked when a demon delivery from the Duke flashed inches from her face when she stepped up to the crease to face her husband's bowling.

Kate soon found her composure and wagged a finger at the Duke, as if to tell him off, and William replied with a mock laugh.

The royal couple were in Christchurch to carry out a number of engagements but the main focus was to pay their respects to victims of the devastating earthquake which struck the city on February 22 2011 leaving more than 180 people dead, and to learn about the reconstruction efforts.

William, who visited the city soon after the natural disaster struck, gave a speech during the day and described how they were moved by reminders of the earthquake and praised the "resilience and adaptability'' of the people.

The royal couple, who are both sporty, happily tried batting and bowling in their formal wear - William in a suit and tie and Kate in a red Luisa Spagnoli skirt suit and three-inch heels.

The Duchess strode to the makeshift crease in Christchurch's Latimer Square, which was ringed by hundreds of well-wishers and was joined by former New Zealand batswoman Debbie Hockley.

After unbuttoning his suit William confidently walked to the other end and began tossing the ball a few inches in the air and chatting to New Zealand's finest cricketer, Sir Richard Hadlee.

The Duke's first delivery was the full toss which flew close to the Duchess' head and Hockley strode forward and indicated the ball was well wide of the crease by holding out her arms.

Kate was ready for the next delivery and strode forward to hit it to short mid-off where it was fielded by one of the young cricketers.

Her husband's next ball flew past the stumps and there was a swing and a miss from the Duchess at the final delivery.

William then got the chance to bat with his wife acting as wicketkeeper and he showed off his skills as he faced the young cricketers.

Despite writing with his left hand, the Duke batted with his right and hit one ball over the heads of the fielders then another almost out of the ground.

New Zealand is hosting the next cricket World Cup with Australia and the trophy was on display nearby and before joining the impromptu game the royal couple had a close look at the silverware.

"I thought they were great sports to take part in it. I couldn't bat in high heels. She's not played before so it's a pretty good effort and she did the best she could."

William gave his speech when he visited the Air Force Museum of New Zealand at Wigram, a former base in Christchurch.

Inside the museum's main exhibition hall housing historic military aircraft, the couple joined 500 people at a Future Focus lunch, organised by the Canterbury Employers' Chamber of Commerce to discuss ideas about how the city should be rebuilt.

Chamber of Commerce officials estimated the cost of rebuilding the city at 50 billion New Zealand dollars (£25 billion) including £10 million for housing and £7 billion for the central business district.

In his address the Duke also sympathised with the people of the Solomon Islands who have experienced two earthquakes in recent days and told the guests how during their tour they were "grateful for the way in which we have been made to feel so very welcome".

He said: "Both Catherine and I have found ourselves moved this morning by the reminders of how awful the second earthquake was, striking as it did out of the blue in the middle of an ordinary day."

William went on to say: "For you in Christchurch, it is inevitable that, after such a shocking and disruptive experience, choices about the way forward will be challenging.

"Yet, what has struck me on this visit - three years on - is the resilience and adaptability of Christchurch. Despite the daunting job ahead of you, life continues with classic Kiwi humour, creativity, innovation and determination. Christchurch remains a buzzing, thriving city.''

Before leaving the royal couple each laid a rose at a memorial wall to all those who have served and died in New Zealand and Allied flying services.

The sombre occasion had a lighter moment when a tiny curtain concealing a plaque commemorating the royal visit to the monument failed to part when William and Kate pulled a draw string.

Earlier the royal couple had visited Christchurch's CTV Building Memorial Park and met families of those who died in the 2011 natural disaster.

The CTV building crumbled to the ground during the 6.1-magnitude earthquake, and its collapse was responsible for nearly two-thirds of the 185 deaths from the quake. A government report later found it was poorly designed and inadequately constructed.

The royal couple went for a walkabout in Latimer Square before playing cricket and at the end of their time shaking the hands of dozens of well-wishers met a group of five twins and their mothers.

The toddlers were mostly 20 months old and lined up in double push chairs and when William saw them he gasped "Wow. What do we have here, They're all so cute!"

During the day the Duke and Duchess were encouraged by a Maori chief to do what "Princes and Princesses do" - and have more children.

Kate appeared to pour cold water on speculation that Prince George could soon have a brother or sister when she told New Zealand wine-makers yesterday she was really enjoying being able to drink again after giving birth.

But during a formal welcome to Christchurch by the indigenous people of the local area, their chief made the royal couple laugh when he urged them to have another child.

At the end of a welcoming speech given outside the city council building Henare Rakiihia Tau, chief of the Ngai Tuahuriri said: "May you do what Princes and Princesses have always done and increase your family."